1. Field of Invention
The invention relates to an image pickup lens assembly and, in particular, to an image pickup lens assembly with a filter lens, which is for absorbing interfering light.
2. Related Art
With reference to FIG. 1, a conventional image pickup lens assembly 1 includes a barrel 11, a first lens 12, a second lens 13, a blocking filter 14, a sensor 15, and a holder 16.
The barrel 11, which includes a container 111 and a diaphragm 112, connects to the holder 16. The first lens 12 and the second lens 13 are accommodated in the container 111. The blocking filter 14 is set on the holder 16.
The sensor 15 is disposed on a substrate 17, such as a printed circuit board or a flexible board. The holder 16 is connected to the substrate 17, and the holder 16 is adhered to the substrate 17.
In this case, the sensor 15 can be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) sensor. The sensor 15 is for receiving a light beam, which enters the diaphragm 112 and passes through the first lens 12, the second lens 13 and the blocking filter 14. Wherein, the blocking filter 14 is used to block the infrared rays and ultraviolet rays that interfere with the sensor 15. In addition, the first lens 12 and the second lens 13 can be aspherical lenses produced by the way of plastic injection molding or glass molding. Alternatively, the first lens 12 and the second lens 13 also can be spherical lenses produced by the way of grinding.
However, when the blocking filter 14 is not clear, such as the particles are deposited on the blocking filter 14, the portion of light beams may be blocked from entering. Therefore, part pixels of the sensor 15 cannot receive the light beams that results in decreasing sensitivity of part pixels. Thus, the image quality is affected. Accordingly, in order to demand the clearness requirement for manufacturing the blocking filter 14, the production yield is low and the manufacturing cost is high. Presently, those skilled people coats multi-layers of infrared rays filter on a curved lens to increase production yield and decrease manufacturing cost. However, the disadvantage experienced with above mentioned process is that relative difficult on manufacturing.
Therefore, according to the above-mentioned problems of the state of the art, it is a subjective to provide an image pickup assembly, which is much easier on manufacturing, less in number of assemblies, as well as has an effect on blocking specific wavelength light.